172. Total energy expenditure in stable patients with cystic fibrosis

Abstract

Background and aims: Undernutrition is a common problem in patients with cystic ¢brosis and is associated with a poor prognosis.The two aims of this study were to assess and compare the two main ¢eld techniques in the measurement of total energyexpenditure and, secondly, to assess total energyexpenditure in stable patients andcom- pare withhealthy controls. Methods:Restingenergyexpenditurewasmeasuredusingindirectcalorimetryandtotalenergyexpenditurewasmea- sured using 24-hheart rate (HR) methodology and doubly isotopically labelled water. Results: Seventeenpatients, meanage 23 years and FEV152%predictedandthirteencontrols were recruited. Resting energy expenditure was higher in patients 0.24 (0.03) MJ/kg Fat-Free Mass (FFM) compared to controls 0.22 (0.02) MJ/kg FFM, P=0.02.Twenty-fourhourheartrateunderestimatedtotalenergyexpenditure,9.49(1.85)MJ/dayinpatients compared to 11.69 (2.79)MJ/day using doubly labelled water. There was no diierence in total energy expenditure in patients and controls using both methods,11.69 (2.79) MJ/day compared to11.38 (2.71) MJ/day using doubly isotopi- cally labelled water. Conclusions: Inclinically stableyoungadultpatientswithmoderately severe respiratorydiseasetotalenergyexpendi- tureiscomparabletothatanacontrolpopulationdespiteinincreaseinrestingenergyexpenditureandboth24-hHRand doubly isotopically labelled waterare suitable foruse inpatients with cystic ¢brosis. & 2001Harcourt Publishers Ltd.